hwmon: (k10temp) Add debugfs support

Show thermal and SVI registers for Family 17h CPUs.
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/k10temp.c

@@ -26,6 +26,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/debugfs.h>
 #include <linux/err.h>
 #include <linux/hwmon.h>
 #include <linux/init.h>
@@ -442,6 +443,76 @@ static bool has_erratum_319(struct pci_dev *pdev)
 	       (boot_cpu_data.x86_model == 4 && boot_cpu_data.x86_stepping <= 2);
 }
 
+#ifdef CONFIG_DEBUG_FS
+
+static void k10temp_smn_regs_show(struct seq_file *s, struct pci_dev *pdev,
+				  u32 addr, int count)
+{
+	u32 reg;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		if (!(i & 3))
+			seq_printf(s, "0x%06x: ", addr + i * 4);
+		amd_smn_read(amd_pci_dev_to_node_id(pdev), addr + i * 4, &reg);
+		seq_printf(s, "%08x ", reg);
+		if ((i & 3) == 3)
+			seq_puts(s, "\n");
+	}
+}
+
+static int svi_show(struct seq_file *s, void *unused)
+{
+	struct k10temp_data *data = s->private;
+
+	k10temp_smn_regs_show(s, data->pdev, F17H_M01H_SVI, 32);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(svi);
+
+static int thm_show(struct seq_file *s, void *unused)
+{
+	struct k10temp_data *data = s->private;
+
+	k10temp_smn_regs_show(s, data->pdev,
+			      F17H_M01H_REPORTED_TEMP_CTRL_OFFSET, 256);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(thm);
+
+static void k10temp_debugfs_cleanup(void *ddir)
+{
+	debugfs_remove_recursive(ddir);
+}
+
+static void k10temp_init_debugfs(struct k10temp_data *data)
+{
+	struct dentry *debugfs;
+	char name[32];
+
+	/* Only show debugfs data for Family 17h/18h CPUs */
+	if (!data->show_tdie)
+		return;
+
+	scnprintf(name, sizeof(name), "k10temp-%s", pci_name(data->pdev));
+
+	debugfs = debugfs_create_dir(name, NULL);
+	if (debugfs) {
+		debugfs_create_file("svi", 0444, debugfs, data, &svi_fops);
+		debugfs_create_file("thm", 0444, debugfs, data, &thm_fops);
+		devm_add_action_or_reset(&data->pdev->dev,
+					 k10temp_debugfs_cleanup, debugfs);
+	}
+}
+
+#else
+
+static void k10temp_init_debugfs(struct k10temp_data *data)
+{
+}
+
+#endif
+
 static const struct hwmon_channel_info *k10temp_info[] = {
 	HWMON_CHANNEL_INFO(temp,
 			   HWMON_T_INPUT | HWMON_T_MAX |
@@ -553,7 +624,12 @@ static int k10temp_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	hwmon_dev = devm_hwmon_device_register_with_info(dev, "k10temp", data,
 							 &k10temp_chip_info,
 							 NULL);
-	return PTR_ERR_OR_ZERO(hwmon_dev);
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	k10temp_init_debugfs(data);
+
+	return 0;
 }
 
 static const struct pci_device_id k10temp_id_table[] = {